Remote control apparatus



April 15, 1941.

J. H. NIECKELS REMOTE CONTROL APFARATUS Filed A ril 12, 1959 2 Sheets-Sheet 1 opoo April 15, 1941. J. H. NIECKELS REMOTE CONTROL AfPARATUS Filed April 12, 1959 I 2 Sheets-Sheet 2 Fiq.2

. for controlling heavy objects.

Patented Apr. 15, 1941 REMOTE CONTROL APPARATUS John Harry Nieckels, Stockholm, Sweden Application April 12, 1939, Serial No. 267,509 In Sweden April 14, 1938 13 Claims.

' This invention relates to an apparatus for the control at a distance of states 01' motion of an object, i. e. its position as a function 01' time, velocity and acceleration, or one or more of these factors dependent upon the nature the motion, from a transmitting device placed at a great or small distance.

The apparatus hitherto known for the control at a distance of the state of motion of an object have been found neither to be capable of working with sufiicient accuracy nor to possess the power required in many cases, for instance The insuflicient accuracy has then resulted partly in a certain error in the desired correspondence between the position of the control member oi the transmitter and that of the controlled member of the receiver, and partly in a certain time-lag (phase diiTerence) before the desired correspondence between their positions is attained, or in both these demerits. Another deficiency oi! some of the apparatus hitherto known is the so-called hunting-effect, which consists in that the controlled member of the receiver does not sufliciently quickly reach the position of balance indicated by the control member of the transmitter but makes oscillations about this position which cannot be damped ou-t sumciently fast to obtain the desired accuracy under all circumstances.

If, for simplicity, the controlling and controlled members are supposed to be replaced by masses concentrated at points, each moving in its own co-ordinate system, and if the variables referring to the co-ordinate system of the controlling member are indicated by small letters and those referring to the system of the controlled member by capital letters, the ideal solution of the problem of the control at a distance requires that at each moment the displacement 8 8 S=S 21:11., and V= V, a=a, A=A,,

where the quantities indicated by the suflix "0 relate to the freely chosen starting positions. It should-be noted that s and S may be three dimensional quantities and that the Equation 1 thus implies that the two mass points each in its co-ordinate system synchronously describe similar curves, where the scale is indicated by K, and that in the samemanner the vectors of the velocity and acceleration vary similarly in the scales L and M, respectively.

Supposing now the two 'mass points to be moving each .by itself without being connected to each other by any transmission system tending to co-ordinate their movements, then during a certain elementary interval From this it is evident that the construction of the transmission system ought to be such as to tend perpetually to reduce the values of As, Au and Aa to zero and to retain them at this value.

The present invention relates to apparatus in which the variations of As, Av and Au or their components along the axes of a co-ordinate system together or each by itself cause apotential difference between two points in an electric circuit which thereafter, if desired by the aid of an amplifier, is used for influencing motors or the like moving the controlled member in the directions of the axes of the co-ordinate system or causing it to rotate, and wherein this action may take place either directly or by means of the controlling device of the motor employed, for example field-rheostats, distributing slidevalves, carburettor throttles or the like. The sole point where the value of As is zero may in that case correspond to the potential-difl'erence zero or another value chosen in advance.

If the three voltages which are in this way caused to correspond to the variations of s, v

and a are connected in series, a resulting electromotive force E is obtained E=As+Av+Aa=E1-Ez (7) where dc (9s Ei=8+a+ (8) and E,=Ks+II+M;- 9

or for .(is d d5 d S E-0 s+ -KS+ W whence it follows that the movements will then be fully identical, uniform and synchronous.

well as in phase and, perhaps, also in frequency.

In the accompanying drawings there is shown diagrammatically in Figure 1 an apparatus according to the invention with a circuit containing condensers, in which as an example only the difference between one of the quantities characterising the states of motion of the controlling and controlled members has been chosen for representation as an impulse voltage, viz. the positions. In Figure-2 there is shown diagrammatically another ,embodiment of the invention in which the difference in value of all the three characteristics of the states of motion of the controlling and controlled members are composed to form an impulse voltage according to the Equation 7.

In Figure l, I indicates the controlling member the shaft 2 of which, ii desired by the aid of a gearing not shown, turns a shaft I or the like on which is fixed a worm 4a or the like meshing with a worm-wheel sector 4b fixed on the same shaft as or connected in another way with the movable plate system of a variable condenser 5. The movable plate system of a second variable condenser 9, which is in the same way connected with a shaft 9 pertaining to the contrblledmember Ii by a worm-wheel sector lb. and}; worm la, rotates or is moved-in'another way. when the shaft 9 rotates.

controlled member, are connected, together with the condensers I and I, each in itsarmoi' a Wheatstone bridge network on which a voltage V is impressed through the conductors 9. To

each angle of turning of the shafts 9 and 9 in relation to each other and thereby also of the controlling member I and the controlled member H relatively to each other corresponds then a certain potential difference Vi or phase-difierence between thevoltages in the fixed plates of the condensers 9 and 9. It is possible in known manner to use this fact in such a way that the shaft 9 is brought to a standstill either when the potential difference V1 is zero or when the voltages in the fixed plates of the two condensers are in phase, or when the potential difference or the.

phase-difference attains a. certain positive or negative value fixed in advance, but with the apparatus constructed in such a manner that this takes place in one and only one mutual position of the movable 7 plate systems in the condensers and I and thereby also ofthe shafts land 9' rections and at exactly the same speed, and therefore the shaft I l of the controlled member, which if desired may be connected with the shaft 9 and the worm-wheel sector lb by means other than a mechanical connection, then remains stationary, If, however, V: or the phase-difference between the voltages on the fixed plates in the condensers I and 8 differs from zero, the shaft 9 and thereby the controlled member i i itself will rotate in one or the other direction, dependent upon the sign of the phase-difference in relation to the starting point chosen. The additional windings l4 and I 6 of the motors i3 and I5 should then be suitably dimensioned so as to cause different field-strengths for the same strength of current. When the state of motion of the controlled member Il approaches or leaves the state of motion of the controlling member I the capacitance of the condenser 6 also approaches or leaves respectively the value corresponding to that of the regulated capacitance of the condenser I.

Two other condensers l0 and l2, II for the controlling member and for the Instead of the electric differentially connected motors of the above described kind other motors or driving arrangements may, naturally, be used for adjusting or controlling the state or motion of the controlled member.

In order to make it possible to disengage the driving arrangement for moving the controlled member in response to the movements of the controlling member, for instance to make it possible to transfer the controlled member quickly to the proximity oi a desired position from another distant position, there are provided in the circuit in the example according to Figure 1 two short-circuiting devices I! and I9 by which the condensers I andl can be short-circuited. Suitably the ap-' paratus according to Figure 2 may also be provided with arrangements of another kind by means of which the condensers, the inductancecoils and the resistances or any of them can be short-circuited for the same purpose.

Figure 2 shows an apparatus according to the invention in which there are used in a circuit 9, connected in the form of a Wheatstone bridge network and fed with a voltage V by a transformer 21 Home circuit the frequency oi which can be varied by means of a variable condenser 22, both resistances and inductances and capacitances for controlling the position, the acceleration and the velocity, respectively, of the controlled member in relation to the controlling member. The bridge circuit 9 includes two potentiometers I and 6 over which the contacts 4 and 1 move. These contact arrangements determine the position of the shafts 9 and 9 of the controlling and controlled members. The variable condensers 23 and 24 are connected by means of levers or in another way with the centrifugal regulators 29 and 29 which are driven from the shafts I and 9, respectively. When the weights of the centrifugal regulators move outwards or inwards the capacitances of the condensers 29 and 24 will vary in proportion to these movements by the movable plate systems 01' the variable condensers then being turned. Simultaneously the iron cores 2'! and 29 inlthe inductance coils 28 and 30 will move axially with a velocity that is a function of the rate of change'of the velocity, 1. e. the acceleration of the shafts Sand 9, respectively. A voltage is thus generated in each branch of the bridge which will be superposed on the alternating current voltage before existing. Between the contact points 4 and I a voltage will thus arise which is the sum of these voltages.

The alternating voltage in turn is the geometric sum of a real part dependent upon the positions of the contacts 4 and 7 on the potentiometer and 8 and an imaginary part dependent upon the capacitancesof the condensers 23 and 24, respectively, which in turn are connected with the speeds of the shafts 3 and 9. Thus the voltage Vi between the contacts will be identical with the disturbance function E defined in the above-mentioned Equation 7. By varying the frequency of the impressed voltage V by means of the condenser 22 it is possible to arrange, if desired, that at a certain given relation between the states of motion of the controlling and controlled members resonance will arise in the circuit 8 and thereby inter alia a more delicate adjustment will be obtained.

The invention is not limited to the apparatus above described or shown in the drawings, which are only cited and shown by way of example and may be varied in many ways in details and construction without exceeding the scope of the in vention.

What I claim as new and desire to secure by Letters Patent of the United States of America is:

1. Apparatus for the remote control of the position of a secondary element in accordance with displacements of a primary element, said apparatus being of the type including a balanced electrical network having a branch containing impedance adjustable by said primary element, a second branch containing impedance adjustable by said secondary element, an input circuit for impressing an alternating current voltage upon the network, an output circuit in which a potential is developed when the workwork is unbalanced. and motor means controlled by potentials developed in the output circuit to adjust said secondary element to re-establish a balance of the network, characterized by the fact that the impedances of said branches are complex and each includes adjustable impedances of different characters, and said primary and secondary elements are connected to the adjustable impedances of different characters to vary the same in accordance with diiference functions of the displacements of the respective elements.

2. Apparatus as claimed in claim 1, wherein each of saidcomplex impedances includes a resistive and a reactive impedance component, one of said impedance components being adjusted in accordance with the position of the associated element and the other impedance component being adjusted in accordance with a function of the motion of the associated element.

3. Apparatus as claimed in claim 1, wherein each of said complex impedances includes a resistive and a reactive impedance component, one of said impedancev components being adjusted in accordance with the position of the associated element and the other'impedance component being adjusted in accordance with the velocity of the associated element.

4. An apparatus for the remote control of the position of a secondary element in accordance with the state of motion of a primary element, said apparatus comprising an electrical network having a pair of balancing branches. an input circuit for imposing an alternating current voltage upon said network, an output circuit in which a potential is developed when said net-- work is unbalanced, each balancing branch including variable impedances of different types, means for adjusting the impedances of diilerent type in one balancing branch by said primary element in accordance with diilerent functions of the motion of that element, means for adjusting the impedances of difierent type in the other balancing branch by' said secondary element in accordance with diiferent functions of the motion of that element, and motor means in said output circuit for displacing said secondary element in response to voltages developed in said output circuit by an unbalance of the network, thereby to re-establish a balance of the network.

5. An apparatus as claimed in claim 4, wherein each of said balancing. branches includes reactive impedances of different types, and means is provided for adjusting the frequency of the imposed alternating current voltage to resonate with said balancing branches of the network at a preselected adjustment of the relative values of the reactive impedances of the branches.

6. An apparatus as claimed in claim 4, wherein the variable impedances oi said balancing branches include resistive and capacitive components.

7. An apparatus as claimed in claim 4, wherein the variable impedances of said balancing branches include resistive and inductive components.

8. An apparatus as claimed in claim 4, wherein the variable impedances of said balancing branches include resistive, capacitive andind'uc-' tive' components.

9. An apparatuses claimed in claim 4, wherein the variable impedances ofsaid balancing branches include a resistance.- and an inductance shunted by a capacity.

10. An apparatus for the control of the position of a secondary element 'in'accordance with position and state of motion of a primary element, said apparatus comprising a Wheatstone bridge network having as the conjugate arms thereof an input circuit for imposing an alternating current voltage upon the bridge and an output circuit inwhich the alternating current potential varies with the unbalance of the bridge, and motor means in saldoutput circuit for displacing said secondary element; opposed balancing arms of the bridge comprising resistances adjustable respectively by said primary and said secondary elements, and the other pair of opposed balancing arms of the bridge comprising reactive impedance adjustable respectively by said. primary and secondary elements.

11. An apparatus for the control of the position of a secondary element in accordance withposition and state of motion of a primary element, saidapparatuscomprising a Wheatstone bridge network having as the conjugate arms thereof an input circuit for imposing an-alternating current voltage upon the bridge and an output circuit in which the alternating current potential varies with the unbalance of the bridge. and motor means in said output circuit for daplacing said secondary element; opposedbalancing arms of the bridge comprising resistances adjustable respectively by said primary and said secondary elements in accordance with the positions of those elements, and the other pair of opposed-balancing arms of the bridge comprising reactive impedance'adjustable respectively by said primary and secondary elements in accordance with a-i'unction of the state of motion of those elements.

12. An apparatus for the control of the position of a secondary element in accordance with position and state ofvmotion of a primary element, said apparatus comprising a Wheatstone 'output circuit in which the alternating current potential varies with the unbalance of the bridge. and motor means in said output circuit for displacing said secondary element; opposed balancing arms of the bridge comprising resistances adjustable respectively by said primary and said secondary elements, and the other pair of opposed balancing arms of the bridge comprising reactive impedances of opposite type adjustable respectively by said primary and secondary elements in accordance with the velocity and the acceleration of those elements.

13. In remote control apparatus, the combination with a primary element, a secondary element, and sets of indicating members connected to the respective elements for displacement thereby to indicate the instantaneous values of the positions, velocities and accelerations of the respective elements, of an electrical network having balancing branches connected between an alternating current input circuit and an alternating current output circuit, pairs of adjustable impedances of three types in said balancing branches, the impedance pair of each type being in difierent branches, whereby the network may be balanced to provide zero current in the output circuit, means for adjusting one impedance of each type by the respective indicating members of the set connected to the primary element, means for adjusting the other impedances by the respective indicating memelement.

JOHN HARRY NIECKELS.

CERTIFICATE OF CORRECTION. Patent No. 2,258,185. April 1 19in.

' JOHN HARRY NIECKELS.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, first column, line 14.7, claiml, for the word "difference" read different-; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 15 th day of May, A. D, 19in.

Henry Van Arsdele,

(Seal) Acting Commissioner of Patents. 

